How do they know atoms exist?

how do they know atoms exist when no one has ever seen it or taken a photo of it?

well i think you didn't see a real one but a artist impression because as far as i know that if you where to magnify a atom the atom's electrons in the lens will cause it to give a very in accurate image.

I agree with Decius. Atoms were originally assumed to exist. But logical conclusions based on assumptions turned out to match experimental data.

I remember seeing photographs showing individual atoms in a crystal. But details were missing--one could not see anything similar to little planetary system.

Ludwik Kowalski (see Wikipedia)
Professor Emeritus
Montclair State University, USA

well kowalskil it would not look like planetary systems as the electrons make a cloud around the nuclei.

anyway, those evidence can be of something that has the same qualities of an atom but could look completely different. the structure could be completely different than the way they think it looks.

Kowalski is referring to the hypothesised diagrams of atoms in which electrons orbit the nucleus.

You wrote:
"Kowalski is referring to the hypothesised diagrams of atoms in which electrons orbit the nucleus."

Thank you for clarifying this. The older model "distinct-planets-like" has been replaced by the newer one "clouds-like." And who knows what models will be found useful in the future?

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Ludwik Kowalski (see Wikipedia)
Professor Emeritus
Montclair State University, USA

I have been told some of the bigger atoms (in 100ish neutron range) are visible with electron microscopes, this doesn't really prove or disprove the atom. Evidence for the nucleus (a cluster of protons and neutrons) come from Rutherford's gold foil experiment, which you can google to learn more about.

Have you guys googled pictures of atoms lately? I did, they claim to have finally done it with atomic? Microscopes. And then provided pics.

those pictures uses electrons they shoot through at one end and then on the other end they look how much has been absorbed but they can not say what is absorbing it. the structure only comes out as a whole so the inside structure could be completely different from what is theorized

Maybe atoms is like all mixed up with no real position for protons and electrons and that they only assemble if it reacts. i say this because there is no real evidence that strong nuclear forces exist as they only made it up to explain the existence of the atom. have you ever thought that maybe there is no rules in the universe and that rules only come up if there is a reaction. i say this because all we see is the rules of the universe but the universe exist inside of nothing and therefore nothing can't have rules therefore the rules of the universe is only a illusion.(please not when i say it exist in nothing i do not mean empty space i mean the nothing around/outside the universe.)

In my opinion, particles are an illusion. Everything is actually waves. If all the waves are in balance, then "nothing" exists. Example: a simple 2dimensional image of a horizontal line represents nothing in the vertical axis. But that does not mean it has no vertical components.

it has an infinitude of vertical potentials, as long as the positive and negative are equal. Just look at a simple wave crest above & an equal but opposite wave through below...they balance each other out to flat line....that is, as long as they are "in phase".

The toal of the universe may equal nothingness but it exists because it is "out of phase".

This is how I picture atoms...
The universe is a continuos cycle of waves.
From the center, the point of maximum energy, they spread out through space in their simplest form. (We envision them as quark particles due to our perspective within the system).

As they cool, by being expanded through space, they recombine with other waves. They never loose their identity but become part of larger structures BECAUSE of their identity in phases.

This means that at a certain level of cooling, quark waves recombine into atomic particles.

At a greater level of cooling, atomic particles recombine into atoms, which combine into matter, which combine into stars, which combine the atoms into more complex atoms allowing for more types of matter, solar syzrems, galaxies, dark matter and dark energy which is, in effect, the "return flow" of the fully recombined waves to the center wher the cycle repeats.

Everything is ultimately these waves in various states of recombination.

We are part of this system, moving with it, we envision "existence through time" only able to perceive "the present".

To objectively understand the universe, we must look at everything in terms of it time line, the wave.

Subjectively, we focus on individual crests, that seem to be particles in our perspective.

I still haven't fully grasped what you've tried to explain in your last post here Humanbean but I did find it interesting that you linked the cooling of the most basic form of matter (which you called "quark particles" - which you say are actually waves) with the creation of more complex forms.

This makes a lot of sense to me because in nature, things that cool a lot of times "crystallize" into more rigid forms. That cooling is linked with complexity...

And are you positing that because of our discrete perception of time (or to use a more accurate word, change), we in turn see everything as discrete instead of flow or wave?

My CTL level has to reach 2 before I can post links (I'm working on that)...

In the mesntime, google, "Dr Quantum double slit rxperiment" and watch related video...

As you can see in this video example, there is a widely held view that everything is "potentials" until "observed"

My theories explain why this is so.

Here's the video. It's been posted before but it's good enough to post again.

http://www.youtube.com/watch?v=TMzh0gTTJI8